in case if something went wrong during updating/flashing your receiver and it fails to start because of missing kernel, emergency partion.. i have created an "emergency-kernel" with an embedded emergency ramdisk - so you can revive your receiver as long as you haven't killed uboot.
follow this steps:
1.) install a tftp-server (windows e.g.
http://perso.orange.fr/philippe.jounin/tftpd32.html)
2.) download the "emergency-kernel" and copy "emergency.ub" to your tftp-share -->
http://www.megaupload.com/de/?d=66RV985P
3.) connect the receiver through serial and network port and start the terminalapplication on the serial port
4.) power on the receiver and press immediately <enter> on the terminal, you should see the uboot prompt (STB7100-Ref>)
5.) on uboot prompt set the box ip with "set ipaddr 192.168.x.x" (you have to adapt x.x to your settings, both have to be in the same subnet)
6.) on uboot prompt set the tftp-server ip with "set serverip 192.168.x.x" (you have to adapt x.x to your settings, both have to be in the same subnet)
7.) on uboot prompt copy the kernel with "tftp a4000000 emergency.ub" into memory
8.) plugin the prepared usb-stick (you can get a full update of all partitions here -->
http://www.megaupload.com/de/?d=63MJTFN9)
9.) on uboot prompt start the kernel from memory with "bootm a4000000"
now the emergency-system should boot and starting to update...
viel spass mit eurem wiederauferstandenen receiver